Frozen materials



Patented arouses zen :1:

bert' Henry Bedford, New York, N. 3!.

Application February 26,

g. Serial No. 192,798, which is a division of ap= plication Serial No.M1337, May 11, 1937. Divided and this application June 27, 1939,

Serial. No. 281,309

6 Claims. (Cl. 99-195) This invention relates to frozen materials, suchas block ice, ice-glazed frozen comestibles and containers in whichfrozen products may be stored or transported.

For many years comestibles,- particularly flesh foods such as fish, havebeen frozen for the purpose of preserving such comestibles until used.Recently, the freezing of comestihles has been eifected by the so-calledquick-freezing processes. In any event, when the fish are frozen, theyare maintained in cold storage until used.

When frozen fish are maintained in cold storage, they are exposed to airand even at very low temperatures, for example -20 0., the rate ofevaporation is comparatively so great that the fish become dry ordehydrated; As a consequence, undesirable changes in the chemical natureof the fish as well as their constituents result.

In order te inhibit evaporation directly from frozen fish under storageor other conditions, the frozen fish are dipped in water whereby anenvelope or glaze of ice completely surrounding the fish is produced.When glazed fish are stored at temperatures below the freezing point ofwater, evaporation of water takes place from the ice glaze instead offrom the fish and thus the evaporation directly from the fish togetherwith the undesirable efiects are eliminated.

The ice glaze produced from ordinary water cracks either immediately inmany places or it cracks in many places after storage. ere

a crack in the glaze appears, there is evaporation of water directlyfrom the cells of that partof the fish and later from the adjacentcells.

Due to the fact that the water glaze is brittle, the

cracking may be increased or indeed the glaze chipped oii, when theglazed fish are moved from one position to another during storage orwhen they are transported.

In the manufacture of ice from distilled water or raw water either bythe plate or can method, the water is frozen at comparatively hightemperatures. When the rate of freezing is hastened by a temperature ofor slightly less than -12 C., the block ice cracks either in the can orwhen the can or plates are being heated for the purpose of melting outthe ice from the container (see Practical Refrigerating EngineersPocketbook by John E. Starr, published by Ice and Refrigeration,Chicago, 1922). Cracked ice shatters when jarred and consequently cannotbe handled economically.

I have now found that I can produce substantially non-cracking ice,either in the form' of a block or as a glaze, from aqueous solutionscontaining an acid.'

It is, therefore, an object of this invention to provide substantiallynon-cracking ice in various forms, such as in the form of block ice oras a glaze on frozen comestibles or as a glaze on containers in whichthe frozen comestibles are packed.

Other objects will appear from the following description and appended clIn accordance with the principles of the instant invention, when a fleshfood such as fish is to be given an ice glaze, the fish are frozen byeither a quick-freezing process or any other freezing process, and thefrozen fish dipped into the-glazing solution. The temperature of theglazing solution is usually at a temperature considerably higher thanboth the temperature of the frozen fish and the temperature of the roomin which the glazing operation is performed. As a consequence, when thefish are dipped into the glazing solution and withdrawn therefrom, theglazing solution adhering to the fish, due to the temperature of thefish and the temperature of the glazing room, is substantiallyimmediately frozen, providing a glaze completely enveloping the fish.The operation may be repeated, the

number of .dippings in the glazing solution depending on the thicknessof the glaze desired.

The glazing solution contemplated by this invention is an aqueoussolutionwhich will produce a non-cracking ice. These results are securedby incorporating acids in the glazing solution. The acids contemplatedby this invention are non-toxic and edible or used in such portions asto be non-toxic and edible. Further, in order to secure the desiredproperties, the acids should be soluble in water and the ice obtainedfrom such aqueous solution should be a homogeneous solid. The acidsshould be of the type which have a minimum of reaction with proteins offish (slime and skin) or the constituents of muscle cells. The acidsshould be substantially free of odor or taste which could be absorbed byslime, skin or muscle. Preferably, also, the acid should possessantiseptic properties whereby the bacterial growth and autolyticactivity in fish are reduced. Various acids may be used. I have foundthe best results are secured when acids of the type and nature ofhydrochloric acid of U. S. P. grade are used.

To more clearly illustrate the nature and principles of the invention,there is hereafter set forth an illustrative embodiment of theinvention:

The concentration in the above specific illustrative embodiment is theminimum concentration for the conditions set forth. However, it is to beunderstood that higher concentrations may be used without departing fromthe spirit of this invention. Usually, however, the minimumconcentration will be used for any particular set of conditions.

Now with respect to the temperature conditions in the specific example,it will be noted that the temperature of the frozen fish is between -30C. and 35 C. and that the temperature of the glazing room is --25 C.These conditions have been selected in order to give the most economicalconditions at a temperature known to be sufficiently low for allpractical purposes. It is to be understood, however, that the inventionis not restricted to these precise temperature conditions. If thetemperature of the frozen fish to be glazed is, for example, at a highertemperature, i. e., C., then the minimum concentration of the substancemight and could be less than stated. If a lower temperature than 35 C.were used, then a higher concentration of the substance set forth wouldhave to be used. The concentration for any particular set of conditionscan be easily determined by simple experiment by any person skilled inthe art.

Fish discolor as a result of discoloration of oils or the growth ofchromogenic bacteria. Some of the cause: which may bring about this are.bacterial decomposition of the cell proteins, while the fish are freshor even if the'fish are frozen and stored at too high a temperature, andthe leakage of ammonia fumes from the cooling coils or refrigeratingsystem coming in contact with.

the frozen fish. By the use of the present invention, the rate ofbacterial growth is markedly reduced or inhibited and the deleteriouseffect, if ammoniacal fumes come in contact with the surface of theglaze, is avoided.

Though in the illustrative embodiment Cohoe salmon is specificallyreferred to, it is to be understood that the invention is not restrictedthereto. The principles of this invention may be applied to othervarieties and species of fish and indeed to flesh food including meat,fruit and vegetables of all kinds and nature.

Glazes on comestibles, such as flesh foods, or on containers produced asaforementioned are non-cracking and smooth. The substance mentionedforms a concentrated solution when the glaze is formed which does notfreeze at the storage temperatures used in practice. The hydrochloricacid solution rises by capillary action to the surface of the glaze,where it forms a film and reduces the vapor pressure characteristics ofthe concentration of the glazingsolution. As a consequence, thecommodity treated with a glazing solution of the type herein describedis preserved for a longer period of time than heretofore.

The principles of the instant invention, as previously mentioned, arealso applicable to the production of block ice possessing thenon-cracking properties. In accordance with this phase of the invention,the selected acid is added to the water and the aqueous solution frozenaccording to the plate or can method. In the plate method, afterfreezing, the plate is heated, whereby the block ice is loosened andremoved. In the can method, after freezing, the can containing the blockof ice frozen therein is immersed into a solution of water at arelatively high temperature, such as 80 C.-100 C., whereby the block iceis loosened from the can and removed. The sudden heating TemperatureChemical 9 53? of brine for freezing C. Hydrochloric acid pH 1.0 --30 Itis to be understood that the invention, with respect to the productionof block ice having noncracking characteristics, is not restricted tothe specific example just given, since it is clear that difierentfreezing temperatures may be employed.

By the use of the instant invention, non-cracking block ice is produced.In addition to possessing the properties which characterize the glazepreviously described, the block ice does not crack during freezing norduring removal from the plate or can. The manufacture or non-crackingblock ice at such low temperatures as herein described has theadditional advantages of reducing the quantity of brine, or surface areaof freezing floor space, required per ton of ice per unit of time andincreasing the ice-producing capacity of the plant when such lowtemperatures are available.

When hydrochloric acid is employed as the acid, the ice, 1. e.,glaze orblock ice, in addition to possessing the characteristics aforementioned,is also substantially transparent and water-white in color.

The term edible as used in the claims is inl tended to cover substanceswhich are edible and non-toxic or used in such proportions as to benon-toxic and edible.

Since it is obvious that various changes and modifications may be madein the above description without departing from the nature or spiritthereof, this invention is not restricted thereto except as set forth inthe appended claims. I

This application is a division of my copending application Serial No.192,798, filed February 26, 1938, which is itself a division ofapplication Serial No. 141,937, filed May 11, 1937.

I claim:

1. Transparent ice formed of water containing hydrochloric acid in anamount to impart noncracking characteristics to said ice.

2. Frozen flesh foods having a transparent ice glaze formed of watercontaining hydrochloric acid in an amount to impart non-crackingcharacteristics to said ice.

3. Frozen fish having a transparent ice glaze formed of water containinghydrochloric acid in an amount to impart non-cracking characteristics tosaid ice.

4. Transparent ice formed of water having a pH of approximately 1 andcontaining hydrochloric acid.

5. Frozen flesh foods having a transparent ice glaze formed of waterhaving a pH of approximately 1 and containing hydrochloric acid.

6. Frozen fish having a transparent ice glaze formed of water having apH of approximately 1 and containing hydrochloric acid.

ROBERT HENRY BEDFORD.

